The use of implanted medical devices is becoming increasingly important in the treatment of diseases and disabilities. Such devices include, but are not limited to, implantable cardiac defibrillators (see e.g., U.S. Pat. No. 5,817,130 to Cox et al., U.S. Pat. Nos. 6,427,083 and 6,418,342 both to Owen, et al.), cardiac pacemakers (see e.g., U.S. Pat. No. 6,421,564 to Yerich, et al. and U.S. Pat. 5,411,537 to Munshi et al., hereinafter the '537 patent), cardiac assist pumps (see e.g, U.S. Pat. Nos. 6,387,037 and 6,299,575 both to Bolling, U.S. Pat Nos. 6,336,939 and 6,346,120 both to Yamazaki, Tevaearai et al., Performance of a New Implantable Cardiac Assist Centrifugal Pump, International Society for Artificial Organs, February 2000 <http://www.cardiacassist.com/research/articles/ASAIO01.pdf>, artificial hearts (see e.g., U.S. Pat. No. 6,346,120 to Yamazaki, et al.), neuromuscular stimulators (see e.g., U.S. Pat. No. 6,163,725 to Peckham, et al.), cochlear implants (see e.g., U.S. Pat. No. 5,344,387 to Lupin, artificial hearing and vision devices (see e.g., U.S. Pat. No. 6,394,947 to Leysieffer (hearing) and U.S. Pat. No. 5,556,423 to Chow, et al. (vision)), deep brain stimulation devices (see e.g., U.S. Pat. No. 6,427,086 to Fischell, et al.), electronic pain blockers, automatic drug delivery (see e.g., U.S. Pat. No. 6,416,493 to Del Giglio), therapeutic alarms/signals (see e.g., U.S. Pat. No. 6,328,699 to Eigler, et al.) and sensor/biotelemetry devices (see e.g., U.S. Pat. No. 6,424,867 to Snell, et al. and U.S. Pat. No. 6,409,674 to Brockway, et al.). As a result, people are experiencing longer and much improved qualities of life. New and more sophisticated bioelectronic devices continue to be developed and it is anticipated that the need for better sources of power will increase, with a growing need for implantable power modules with improved reliability, safety and cost-effectiveness. The present invention results from extensive research and development in the area of implantable electrical power sources, particularly rechargeable batteries and their associated devices.
Numerous electrically powered medical devices have been implanted in recent years. Power to operate these devices has been provided from an external source or, if implanted, a power source has been specifically designed for each particular device.
The need for a standardized power source around which a wide variety of medical devices may be designed, and one which is rechargeable by transcutaneous induction has to date not been met. Moreover, such a power module could be located remotely from a medical device (e.g., an atrial assist pump), minimizing stress on the patient by placing it in a more spacious body cavity (e.g., a subcutaneous pocket created in the abdomen). Such an integrated power source would give significantly increased design flexibility to designers of implantable medical devices. The present invention overcomes the limitations inherent in having to provide external power, external recharging connections, or surgically-replaceable primary batteries for implantable medical devices. Moreover, it overcomes the limitations of other implantable batteries with inductively charged batteries, allowing broad flexibility for design of implantable medical devices. In addition, the present invention overcomes the difficulties associated with precisely locating the implanted secondary charging coil to maximize charging efficiency.
A primary objective of the present invention is to provide an implantable power module (hereinafter “IPM”) containing an energy storage device (e.g., a battery), a PMC, and an MICS for remote communication.
A further objective of the invention is to provide an IPM with one or more homing devices or internal functions for easily locating the device once implanted for possible explant, medical treatment, or recharging purposes.
A further objective of the invention is to provide an IPM incorporating safety devices and design aspects to prevent overheating in the event of a malfunction such as an internal or external short circuit, overcharging, overdischarging, or breach of the battery case.
Yet a further objective of the invention is to provide an EPM that allows inductive recharging of the energy storage device without excessive inductive heating of any portion of the EPM or associated medical devices.
A further objective of the invention is to provide a means for precisely locating a secondary charging coil, or any other implanted device.